/**
 * Program 4.6 Equivalence-relations ADT interface
 * ------------------------------------------------
 * The ADT interface mechanism makes it convenient for us to encode
 * precisely our decision to consider the connectivity algorithm in terms 
 * of three abstract operations: 
 * - initialize, 
 * - find whether two nodes are connected, and 
 * - perform a union operation to consider them connected henceforth.
 * ------------------------------------------------
 */


void UFinit(int);

int UFfind(int, int);

void UFunion(int, int);